1. Field of the Invention
The present invention generally relates to a user interface apparatus for use with a machine which can receive natural language instructions to reach one of a plurality of possible states.
2. Description of Related Art
Achieving the most efficient method of interfacing a user with a machine is a problem that has been given a great deal of consideration in the prior art. In one form of interface, a formal language is used for interaction between the user and the machine. An example of a formal language interface is the interface used in a telephone which has a number of buttons and a rigid specification for what happens when a certain sequence of buttons is pressed. The problem with this type of formal language interface is that it is not flexible and requires the user to learn the formal instructions required.
In another type of interface, a natural language interface is used which allows input in many different ways. A natural language interface allows the user to input an instruction in a more or less unrestricted way. Although the demand for learning using a natural language interface is low, when a machine is first used, or when a machine is used infrequently, users can feel uncertain about how to instruct a machine efficiently. The user may not know what words to use or how to phrase the instruction. They may use unusual words or words that are hard for the machine to recognise or understand. The user may not realise that something can be input in a simpler form. A user may spend a lot of time meandering around the various options a machine has available and then after some time arrive at the instruction that they are satisfied with. A user may then be left wondering how they could specify this instruction more efficiently or directly. If the machine has another mode of input e.g. buttons of a formal language interface, the user may specify instruction using the buttons of the formal language interface. The user may then be curious as to how the instruction could have been entered using the natural language interface.